Print system capable of inhibiting deformation of printing paper due to drying of ink and print method thereof

ABSTRACT

A technique is provided which sufficiently inhibits deformation of printing paper resulting from drying of ink on the paper. When the amount of ink ejected during which the front end of the printing paper is moved, after entered into a counter area facing a print head, to a determination point exceeds the ink amount “enough to cause deformation” of the printing paper, the front end of the printing paper is moved from the determination point to a hold position located downstream thereof and left there for a predetermined time. Thus, the shape of the front portion of the printing paper is maintained, and the deformation of the printing paper due to the drying of ink is prevented.

BACKGROUND OF THE INVENTION

i) Technical Field of the Invention

This invention relates to a print system that can inhibit deformation ofprinting paper resulting from drying of ink on the paper, and a printmethod for the print system.

ii) Description of the Related Art

At the present day, a printer is widely known which ejects ink onto asurface of a printing paper while the paper is being transferred from afeed position to a discharge position for printing (so-called ink jetprinter).

In this type of printer, the printing paper is often curled up gently ifthere is much ink; that is, much moisture, ejected onto the surface ofthe printing paper. In this case, the printing paper may not be insertedbetween a pair of discharge rollers properly, causing a paper jam insidethe printer.

For this reason various techniques to prevent such curling of theprinting paper have been proposed these days. For instance, theUnexamined Patent Publication No. 9-62397 discloses a technique ofslowing down the transfer speed of the printing paper when a paper jamis detected in a state that the amount of ink ejected by a print headhas become more than a predetermined amount. This technique allowsmoisture on the printing paper to be reduced when there is too much inkejected on the surface of the printing paper. By slowing down thetransfer speed of the printing paper, more time is secured for dryingthe ink on the printing paper and thus the curling of the printing papercan be inhibited.

However, the aforementioned technique merely slows down the transferspeed of the printing paper. The shape of the printing paper cannot bemaintained during the time the ink on the paper is being dried.Consequently, the printing paper is sometimes deformed partially whilethe ink is being dried.

If such deformation occurs immediately after the printing onto theprinting paper is started, that is, on the front portion of the printingpaper, there is a fear that a portion of the printing paper may comeclose to or come into contact with the print head and the printingquality may be deteriorated. Furthermore, if large deformation occurs inthe printing paper with a high water absorption rate, the printing papermay be torn by the scan of the print head or may cause a paper jam forthe reason that the printing paper is not inserted between the dischargerollers properly.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a technique thatsufficiently inhibits deformation of printing paper following the dryingof ink on the printing paper.

In order to attain the above object, a print system of the presentinvention comprises a print head that ejects ink, an upstream transferdevice, a downstream transfer device and a print instruction device. Theupstream transfer device is provided in a feed path extending from afeed position to a counter area facing the print head. The upstreamtransfer device transfers a recording medium along the feed path. Thedownstream transfer device is provided in a discharge path extendingfrom the counter area to a discharge position. The downstream transferdevice transfers the recording medium along the discharge path. Theprint instruction device provides instructions for the upstream transferdevice or the downstream transfer device to transfer the recording mediaand for the print head to eject ink, alternately based on print data, sothat a predetermined image is printed onto the recording medium. Theprint data represents an ink ejection pattern of the predeterminedimage.

The print system further comprises an ink amount measurement device andan ink amount determination device. The ink amount measurement devicemeasures the amount of ink ejected from the print head and stores theamount as a measurement value. The ink amount determination devicedetermines whether the measurement value in the ink amount measurementdevice exceeds a preset value when the recording medium is transferredby the upstream transfer device and the front end of the recordingmedium is moved to a first position. The downstream transfer device iscomprised of a drive roller and a driven roller. The recording medium ispassed through between the drive roller and the driven roller.

When it is determined by the ink amount determination device that themeasurement value exceeds the preset value, the print instruction devicediscontinues the instructions based on the print data, and instructs theupstream transfer device to transfer the recording medium from the firstposition to the downstream transfer means. After the recording medium istransferred to the downstream transfer device by the instructions of theprint instruction device and held between the drive roller and thedriven roller, the print instruction device further instructs theupstream transfer device to transfer the recording medium to a secondposition. The second position is the position where the printing shouldbe performed after the printing at the first position is completed. Thesecond position is located at least downstream of the first position.After the front end of the recording medium is moved to the secondposition, the instructions based on the print data are resumed.

According to the above print system, when the amount of ink ejected onthe front portion of the recording medium exceeds the predeterminedamount, the image printing based on the print data is discontinued.Then, after the recording medium is transferred from the first positionto the downstream transfer device, the front end of the recording mediumis moved to the second position, and the image printing based on theprint data is continued. Here, the recording medium is transferred tothe downstream transfer device and the front portion of the recordingmedium is held between the drive roller and the driven roller composingthe downstream transfer device. Consequently, the front portion of theprinting paper is kept straightened by being caught by both upstream anddownstream transfer mechanisms and the evenness on the front portion ismaintained. Thus, deformation of the recording medium due to the dryingof ink can be inhibited.

The print data shows an ink ejection pattern from the print head. Theprint head ejects ink according to this pattern.

The ink amount measurement device is the device that measures the amountof ink ejected from the print head. The ink amount measurement devicemay be designed to measure the amount of ink based on the number of inkdrops ejected from the print head.

Particularly, the ink amount measurement device can be designed tocomprise a drop counter which counts the number of times the printinstruction device instructs the print head to eject an ink drop, or adot counter which counts the number of times of ink drop ejection whichcan be specified by the ejection pattern indicated in the print data,for example.

The above mentioned print instruction device may be designed to instructthe upstream transfer device to transfer the recording medium to thesecond position immediately after the recording medium is transferred tothe downstream transfer device and the front end of the recording mediumis held between the drive roller and the driven roller. However, therecording medium may be left for a predetermined time in a state thatthe front end of the recording medium is being held between the driveroller and the driven roller.

The print system constituted with this preference can reliably preventthe deformation of the printing paper due to the drying of ink.

The “predetermined time” in this constitution may be interpreted as thetime assumed to be required for drying the ink on the recording mediumor the time required till a portion of the printing paper which isdeformed due to the moisture of ink is recovered to its original stateas the ink is being dried.

In the aforementioned upstream transfer device, when the transferdirection of the recording medium is reversed, there is a fear that anerror may occur in the transfer amount owing to the structure of thetransfer mechanism. That is, if the recording medium is returneddirectly to the first position from the downstream transfer device, theposition where the image printing should be resumed is misaligned,resulting in deterioration of the print quality.

Accordingly, it is preferable that the print system of the presentinvention is designed as follows. That is, after the recording medium istransferred to the downstream transfer device and left there for awhile, the print instruction device instructs the upstream transferdevice to transfer the recording medium from the downstream transferdevice to a third position. The third position is a position spacedapart from the first position by a predetermined distance on the side ofthe feed position. When the front end of the recording medium is movedto the third position, the print instruction device instructs theupstream transfer device to transfer the recording medium from the thirdposition to the first position. After the front end of the recordingmedium is moved to the first position, the instructions based on theprint data are resumed.

According to the print system constituted as above, the front end of therecording medium is moved to the third position on the side of the feedposition beyond the first position, after the recording medium istransferred to the downstream transfer device and left for a while.Then, the recording medium is returned to the first position from thethird position and the image printing based on the print data isresumed. Since the transfer direction of the recording medium is notreversed at the first position, misalignment of the position where theimage printing should be resumed is avoided, and high print quality isachieved.

The aforementioned ink amount determination device determines whetherthe measurement value in the ink amount measurement device exceeds apreset value. The ink amount determination device is designed todetermine whether the ink amount ejected from the print head has reachedto the sufficient amount which is assumed to make the front portion ofthe recording medium easy to deform, for example.

The ink amount determination device may also be designed to change thepreset value used for the determination of the measurement valuecorresponding to parameters of the recording medium.

Particularly, the print system of the present invention preferablycomprises a recording medium parameter acquisition device that obtainsparameter data representing parameters of the recording medium from theoutside. The ink amount determination device modifies the preset valueused for the determination of the measurement value according to theparameters shown as the parameter data obtained by the recording mediumparameter acquisition device.

The recording medium parameter acquisition device with this preferencemay be designed to receive the parameter data from other apparatus whichcan be communicated with the present print system for data exchange, forexample. The parameters may be obtained by way of a user input as well.

In order to obtain the parameters from a user input, it is preferablethat the present print system particularly comprises a parameter inputdevice that allows a user to input parameters of the recording medium,for example. The recording medium parameter acquisition device obtainsthe parameters inputted from the parameter input device as the parameterdata.

The aforementioned recording medium parameter acquisition device may bedesigned to obtain data representing the size of the recording medium asa parameter of the recording medium.

According to the print system constituted as above, the datarepresenting the size of the recording medium can be obtained as theparameter data. The ink amount determination device can change thepreset value used for the determination of the measurement valueaccording to the size of the recording medium.

It is preferable that the recording medium parameter acquisition deviceobtains data representing the thickness of the recording medium.

The print system constituted as such can obtain the data representingthe thickness of the recording medium as the parameter data. Thus, thetime during which the recording medium is held between the rollers canbe changed depending on the thickness of the recording medium.

It is preferable that the recording medium parameter acquisition deviceobtains data representing the material of the recording medium.

The print system constituted as such can obtain the data representingthe material of the recording medium as the parameter data. Thus, theink amount determination device can be switched to between execution andnon-execution of the determination depending on the material of therecording medium.

It is preferable that the print system of the present invention furthercomprises a switching device that switches the operation mode of theprinting system according to the instructions from the outside. Thereare two modes to be switched to; a suspension mode and a regular mode.In the suspension mode, the instructions based on the print data fromthe print instruction device are interrupted according to thedetermination result of the ink amount determination device. In theregular mode, the instructions based on the print data are notinterrupted regardless of the determination result of the ink amountdetermination device.

The mode switching device in this constitution is preferably designed toswitch the operation mode according to the input instructions from theoutside of the print system, for example. If the print system comprisesan operation portion that receives a user input, the operation mode maybe switched depending on the user input.

The print system described so far can be either a single apparatus(printer) or a combination of a plurality of apparatus.

For example, a printer and a terminal apparatus which can becommunicated to each other for data exchange may constitute the printsystem of the present invention. In this case, the printer comprises theprint head, upstream transfer device, downstream transfer device andprint instruction device. The terminal apparatus comprises the inkamount measurement device and the ink amount determination device.

The printer of the above print system may comprise the recording mediumparameter acquisition device, parameter input device and/or modeswitching device as mentioned above.

To the contrary, the terminal apparatus may comprise such recordingmedium parameter acquisition device, parameter input device and/or modeswitching device.

Another aspect of the present invention provides a print method in aprint system comprising a print head that ejects ink, an upstreamtransfer device and a downstream transfer device. The upstream transferdevice is provided in a feed path extending from a feed position to acounter area facing the print head. The upstream transfer devicetransfers a recording medium along the feed path. The downstreamtransfer device is provided in a discharge path extending from thecounter area to a discharge position. The downstream transfer devicetransfers the recording medium along the discharge path. The downstreamtransfer device is made up of a drive roller and a driven roller. Therecording medium is passed through between the rollers.

Particularly, this print method is used when an image is printed ontothe recording medium by alternate instructions for the upstream transferdevice to transfer of the recording medium or the downstream transferdevice and for the print head to eject ink, based on print data showingan ink ejection pattern of a predetermined image. In the method, theamount of ink ejected by the print head is measured. Then, when therecording medium is transferred by the upstream transfer device and thefront end of the recording medium is moved to a first position, it isdetermined whether the measurement value measured by the ink amountmeasurement device exceeds a preset value. The instructions based on theprint data are discontinued if it is determined that the measurementvalue exceeds the preset value and the upstream transfer device isinstructed to transfer the recording medium to the downstream transferdevice from the first position. The upstream transfer device is furtherinstructed to transfer the recording medium to a second position whenthe recording medium is transferred to the downstream transfer deviceand the front end of the recording medium is held between the driveroller and the driven roller. The second position is the position wherethe printing should be performed after the printing at the firstposition is completed. The second position is located at leastdownstream of the first position. The instructions based on the printdata are continued after the front end of the recording medium is movedto the second position.

In this print method, the amount of ink may be measured based on thenumber of ink drops ejected from the print head.

It is preferable that the front end of the recording medium is heldbetween the drive roller and the driven roller and left in that statefor a while.

It is preferable that the upstream transfer device is instructed totransfer the recording medium to a second position from the downstreamtransfer device after the recording medium is transferred to thedownstream transfer device and the front end of the recording medium isheld between the drive roller and the driven roller. The second positionis a position spaced apart from the first position by a predetermineddistance on the side of the feed position. In this case, when the frontend of the recording medium is moved to the second position, theupstream transfer device is instructed to transfer the recording mediumto the first position from the second position. After the front end ofthe recording is moved to the first position, the instructions based onthe print data are resumed.

It is further preferable that parameter data representing parameters ofthe recording medium is obtained from the outside. Depending on theparameters indicated in the parameter data, the value used for thedetermination of the measurement value may be modified.

It is further preferable that the parameters of the recording medium asthe parameter data are obtained by a user input.

The operation mode of a print system employing the above print methodmay be switched between two modes: a suspension mode and a regular mode,according to the instructions from the outside. In the suspension mode,the instructions based on the print data are interrupted according tothe determination result on whether the measurement value exceeds thepreset value. In the regular mode, the instructions based on the printdata are not interrupted regardless of the determination result.

The above print method can be implemented on a computer system. In thiscase, respective steps in the print method are executed as a computerprogram.

The program comprises a series of commands to be processed in a computersystem. This program may be supplied to a print system, a printer, aterminal apparatus, a computer system or a user who works on theaforementioned, via a recording medium such as a FD, a CD-ROM, a memorycard, etc. or a transmission line such as Internet, for example. Theprogram is executed in a computer system embedded in a print system, aprinter and a terminal apparatus or in a computer system capable ofcommunicating with a print system, a printer and a terminal apparatus bywire or by radio.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example, with referenceto the accompanying drawings, in which:

FIG. 1 is a perspective view showing an external appearance of a complexapparatus of an embodiment;

FIG. 2 is a block diagram showing a control system of the complexapparatus of the embodiment;

FIG. 3 is a cross sectional view showing a constitution of a feedportion and a print portion;

FIG. 4 is a perspective view showing an external appearance of a platen;

FIG. 5 is a flowchart showing steps of a print process;

FIGS. 6A, 6B, 6C and 6D are illustrations showing how a printing paperis transferred;

FIG. 7 is a flowchart showing steps of a paper size designation process;

FIGS. 8A, 8B and 8C are illustrations showing how the printing paper istransferred on the platen;

FIGS. 9A and 9B are illustrations showing how the printing paper istransferred on the platen;

FIG. 10 is a flowchart showing steps of a print data transmissionprocess;

FIG. 11 is a flowchart showing steps of a print process according toanother embodiment;

FIG. 12 is a flowchart showing steps of a print process according toanother embodiment; and

FIG. 13 is a flowchart showing steps of a print data transmissionprocess according to another embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT First Embodiment

A complex apparatus 1 is an apparatus that serves as a printer, a copymachine, a scanner, a fax machine and a phone. As shown in FIG. 1, thecomplex apparatus 1 comprises a feed portion 10 provided at the back ofthe apparatus body, a user interface portion (hereafter, referred to asa user I/F) 20 provided at the front of the upper face of the apparatusbody, a scanner portion 32 provided at the back of the upper face of theapparatus body, and a discharge tray 34 provided at the front of theapparatus body.

The complex apparatus 1 further comprises a control portion 40 thatcontrols the overall operation of the complex apparatus 1 and a printportion 50 that performs printing onto a printing paper, as shown inFIG. 2, other than the aforementioned feed portion 10 and the scannerportion 32.

The feed portion 10 is composed of a feed roller 12 that transfers aprinting paper set on a feed tray 11 toward the print portion 50, a feedmotor 13 that rotates the feed roller 12 and a feed drive circuit 14that drives the feed motor 13, as shown in FIGS. 2 and 3.

The user I/F 20 comprises an operation keypad 22 with various keysincluding numeric keys, selection keys used for a later-explained papersize designation process (FIG. 7), etc., a display panel 24 thatdisplays various information, and a speaker portion 26 composed of aspeaker and a drive circuit for activating a speaker.

The control portion 40 comprises a CPU 41, a ROM 42, a RAM 43, a PCinterface (hereafter, referred to as a PCI/F) 44, NCU (network controlunit) 45, etc. All the components of the control portion 40 areconnected to each other via a bus 46. Among the above components, theCPU 41 controls the overall operation of the complex apparatus 1 byfollowing the process steps stored in advance in the ROM 42. The CPU 41stores the result of the process in the RAM 43 and simultaneouslytransmits commands to the respective components of the complex apparatus1 via the bus 46. The PCI/F 44 is an interface that allows the complexapparatus 1 to communicate with a known personal computer (hereafter,referred to as a PC) 100 via a communication cable. The NCU 45 is aninterface that connects the complex apparatus 1 with a communicationnetwork 200.

The print portion 50 comprises a carriage 52 provided with a print head51, a carriage motor 53 that moves the carriage 52 in a primary scanningdirection (direction orthogonal to a transfer direction of a printingpaper), a transfer mechanism 54 that transfers the printing paper fedfrom the feed portion 10 to a counter area facing to the print head 51,a discharge mechanism 55 that delivers the printing paper transferredfrom the transfer mechanism 54 to the discharge tray 34, an encoder 56that detects the amount of the printing paper transferred by eachmechanism 54, 55, a drive circuit 57 that drives the print head 51,carriage motor 53, transfer mechanism 54 and discharge mechanism 55.Among the above components, each of the transfer mechanism 54 and thedischarge mechanism 55 is composed of a motor 54 a, 55 a to be driven bythe drive circuit 57, a drive roller 54 b, 55 b to be rotated by themotor 54 a, 55 a, and a driven roller 54 c, 55 c. The driven roller 55 cof the discharge mechanism 56 is a star-shaped roller having astar-shaped cross section. One and the same motor may be used for themotor 54 a, 55 a that drives each of the transfer mechanism 54 and thedischarge mechanism 65.

As shown, in FIG. 3, in a path from the transfer mechanism 54 to thedischarge mechanism 55 in the print portion 50, a platen 60 is providedthat guides a printing paper to be transferred along the path.

As shown in FIGS. 3 and 4, the platen 60 comprises a plurality of feedribs (projected portions) 62 and a plurality of discharge ribs 64. Thefeed ribs 62 extend from an end of the platen 60 on the side of thetransfer mechanism 54. The discharge ribs 64 extend from an end of theplaten 60 on the side of the discharge mechanism 55. Both the feed ribs62 and the discharge ribs 64 are formed in parallel to the transferdirection of a printing paper. The printing paper is passed over on therespective feeds ribs 62, clearance 66 created between each of the ribs62, 64, and discharge ribs 64. The printing is performed when theprinting paper is on the feed ribs 62.

The feed ribs 62 are configured so that the horizontal position of thefeed ribs 62 with respect to the body part of the platen 60 (verticaldirection in FIG. 3 drawing) is higher than that of the discharge ribs64. There are areas where both of a feed rib 62 and a discharge rib 64are successively provided in the transfer direction of the printingpaper and where only a feed rib 62 or a discharge rib 62 is provided inthe transfer direction of the printing paper. In the area 60 a whereonly a discharge rib 64 is provided, one end of the discharge rib 64 onthe side of the transfer mechanism 54 is chamfered.

(Print Process by CPU 41)

Steps in the print process performed by the CPU 41 of the controlportion 40 are described below by way of FIG. 5. The print process isstarted when the print data is inputted via the scanner portion 32,PCI/F 44 or NCU 45, The print data represents an ink ejection pattern ofan image generated by the print head 51. Particularly, the print data isan array of sub-data. Each sub-data includes the ink ejection patternfrom the print head 51 and the transfer amount of the printing paper inone primary scan. The sub-data are provided as much as the number ofsecondary scan times required for printing the whole image in one pieceof printing paper.

First of all, a paper is fed from the feed portion 10 to the printportion 50 (S110). In this step, the feed roller 12 of the feed portion10 is rotated to feed the printing paper to the print portion 50.

Next, a drop counter is cleared (S120). The drop counter is provided forcounting the number of drops ejected from the print head 61 for theprinting. The number of ink drops is incremented every time an ink dropis ejected from the print head 51 from step S120 onward. The number ofink drops used in so-called flushing is not counted, since those inkdrops are not ejected onto the printing paper but ejected in a space forflushing. Flushing is performed for the purpose of preventing inkclogging.

Next, a piece of sub-data corresponding to one primary scan is taken outof the print data (S130). If this step S130 is to be performed more thanonce after the present print process is started, the sub-data to betaken out for the second time and afterward is the sub-datacorresponding to the next primary scan. The sub-data corresponding tothe next primary scan is the sub-data corresponding to one primary scanto be followed after the last primary scan. The sub-data correspondingto the last primary scan is the sub-data taken out most recently in stepS130.

Next, it is determined whether the front end t of the printing paper hasreached to a determination position (first position) p1 in the counterarea facing the print head 51 after the next secondary scan (S140). Inthis step, whether the front end t of the printing paper has reached tothe determination point p1 is checked according to the output of theencoder 56 (see FIG. 6A). Accordingly, in step S140, positivedetermination can be made only once per one piece of printing paper.

If it is determined that the front end t of the printing paper hasreached to the determination point p1 after the next secondary scan instep S140 (S140: YES), it is checked whether the print state so far isregarded as “heavy-duty” based on the count value in the drop counter(S150). In this step, the ink amount determined from the count value inthe drop counter is regarded as the ink amount ejected from the printhead 51 onto the printing paper during which the front end t of theprinting paper, after entered into the counter area A, is moved to thedetermination position p1. The state in which it is assumed that the inkamount is enough to cause deformation of the printing paper isdetermined “heavy-duty”. Here, the ink amount “enough to causedeformation” is the ink amount obtained by experiments in advance. Theamount becomes large as the size (width) of the printing paper becomeslarge. In the present embodiment, when it is determined whether theprint state is “heavy-duty”, the ink amount is used that is “enough tocause deformation” corresponding to the paper size indicated in the sizedata stored in the RAM 43. The size data represents the paper sizedesignated in a later-explained paper size designation process (FIG. 7).The drop counter counts the number of ink drops ejected during a singleprimary scan. Accordingly, one determination value for determiningwhether the print state is “heavy-duty” is provided per size of paperhaving a different primary scan length.

The ink amount determined “heavy-duty” is the ink amount “enough tocause deformation of the printing paper”. Therefore, the ink amount usedfor the determination is not changed by resolution at recording. Here,the amount of ink ejected from all the nozzles of the print head 51 inthe normal printing mode (150 dpi) is used as the base. Accordingly, ifthe amount of an ink drop is constant, the determination of the printstate can be made by counting the number of the ejected ink drops. Ifthe amount of an ink drop is reduced as in the case of printing in highresolution, the number of times when the determination is performed isincreased.

In step S150, if the print state is determined “heavy-duty” (S150: YES),the printing paper is transferred to the discharge mechanism 55 (S160).In this step, the drive rollers 54 b, 55 b are rotated while thetransfer amount of the printing paper known from the output of theencoder 56 is being checked. Consequently, the front end t of theprinting paper is moved to the hold position ph to be held between therespective rollers 55 b, 55 c of the discharge mechanism 55 (see FIG.6B). The hold position ph to which the front end t of the printing paperis moved can be a position beyond the rollers 55 b, 55 c of thedischarge mechanism 55, so that the front end t may protrude on the sideof the discharge tray 34. When the distance between the front end t ofthe printing paper and the discharge mechanism 55 becomes smaller than apredetermined distance, the rotation speed of the drive rollers 54 b, 55b is decreased so that the transfer speed of the printing paper is alsodecreased. In this manner, deformation of the front portion of theprinting paper resulting from a collision of the front end t against therespective rollers 55 b, 55 c of the discharge mechanism 55, is avoided.

Next, the front end t of the printing paper is held between therespective rollers 55 b, 55 c of the discharge mechanism 55 for apredetermined time (four seconds in the present embodiment) (S170). Thepredetermined time is experimentally determined in consideration of thetime assumed necessary to dry the ink ejected onto the printing paperand the time required for recovery of a portion of the paper from thedeformation due to ink moisture.

Next, the front end t of the printing paper is moved to a recoveryposition (third position) p3 which is spaced apart from thedetermination position p1 in the counter area A by a predetermineddistance (5 mm in the present embodiment) on the side of the transfermechanism 54 (S180). In this step, the drive rollers 54 b, 55 b arerotated while the transfer amount of the printing paper, that is, theoutput of the encoder 56, is being verified. Consequently, the front endt of the printing paper is moved to the recovery position p3 (see FIG.6C). The transfer speed of the printing paper to the recovery positionp3 is made slower than that to the hold position ph. This is because thetransfer of the printing paper to the recovery position p3 correspondsto operation of drawing the printing paper backward. This operation isassumed to apply a heavier load on the paper than that applied by theoperation of drawing the paper forward.

Next, the printing paper is transferred to a position in the counterarea A where the front end t is allowed to reach the determinationposition p1 after the next secondary scan (S190). In this step, thedrive rollers 54 b, 55 b are rotated while the transfer amount of theprinting paper known from the output of the encoder 56 is being checked.Consequently, the printing paper is transferred to the position wherethe front end t is allowed to reach the determination position p1 afterthe next secondary scan (see FIG. 6A).

After step S190 is completed in the above manner, the printing paper istransferred to its normal transfer direction as much as the transferamount indicated in the data taken out in step S130 (i.e. to a secondposition p2; see FIG. 6D) (S200), in the same manner as when it isdetermined that the front end t of the printing paper has not reachedthe determination position p1 in step S140 (S140: NO) or when it isdetermined that the print state is not “heavy-duty” in step S150 (S150:NO). The second position p2 is the position where the printing should beperformed next to the printing at the determination position p1. In thisstep, the drive rollers 54 b, 55 b are rotated to transfer the printingpaper while the transfer amount of the printing paper, that is, theoutput of the encoder 56 is being verified.

Next, ink is ejected from the print head 51 according to the ejectionpattern indicated in the data taken out in step S130 while the printhead 51 (carriage 52) is moved to the primary scanning direction by thecarriage motor 53 (S210). As a result, the image corresponding to asingle primary scan is printed on the printing paper. The count value isincremented by the drop counter.

Next, whether there is the data corresponding to the next primary scanis checked (S220). If the data exists (S220: YES), the process returnsto step S130.

In this manner, steps S130 to S220 are repeated till there is no datacorresponding to the next primary scan. If no data exists in step S220(S220: NO), the printing paper is discharged from the print portion 50to the discharge tray 0.34. The present print process is ended. In stepS230, the discharge mechanism 55 is operated till the printing paper istransferred to the discharge tray 34.

(Paper Size Designation Process by CPU 41)

Steps in the paper size, designation process performed by the CPU 41 ofthe control portion 40 are described below by way of FIG. 7. The papersize designation process is started when a paper selection key on theoperation keypad 22 of the user I/F 20 is depressed.

The CPU 41 stands by till the paper size is designated by the user(S310). After the paper selection key is depressed, the user can operatethe operation keypad 22 to designate the size of the paper which is setor to be set. The paper size to be designated are “letter”, “A4”, “B5”,“A5”, “B6”, “post card” and “L-form”. In this step S310 the CPU 41stands by till the operation of selecting one of the above paper sizesis performed.

When the paper size is selected in step S310 (S310: YES), the chosenpaper size is determined to be the paper size of the printing paper tobe used for printing an image (S320). In this step, the size datarepresenting the chosen paper size is recorded in the RAM 43 in order todetermine the paper size of the printing paper for the image printing.This size data is the data to be used in step S150 of FIG. 6. Accordingto the determined paper size, the determination value, used fordetermining whether the print state is “heavy-duty”, is changed.

[Effects in First Embodiment]

According to the complex apparatus 1 in the present embodiments if theamount of ink ejected on the front portion of the printing paper exceedsthe ink amount “enough to cause deformation” of the printing paper, theimage printing based on the print data is interrupted. The amount of inkejected on the front portion is the amount of ink ejected from the printhead 51 till the front end of the printing paper reaches to thedetermination position p1 after the entry into the counter area A.During the interruption, steps S160 to S190 in FIG. 5 are performed. Thefront end t of the printing paper is moved from the determinationposition p1 to the hold position ph in step S160, and then returned tothe determination position p1 in step S190. The printing based on theprint data is resumed at this point. When the front end t of theprinting paper is moved to the hold position ph, the front end t is heldbetween the drive roller 55 b and the driven roller 55 c making up thedischarge mechanism 55. Consequently, the front portion of the printingpaper is kept straightened by being held respectively between therollers 54 b, 54 c of the transfer mechanism 54 and between the rollers55 b, 55 c of the discharge mechanism 55. Thus, the deformation of theprinting paper due to drying of ink can be avoided.

In step S170 of FIG. 5, the front portion of the printing paper is leftin a state of being held between the rollers 55 b, 55 c of the dischargemechanism 55 for a predetermined time (four seconds). Therefore,deformation of the printing paper due to the drying of ink on theprinting paper can be reliably prevented within the predetermined time,

The front end t of the printing paper is moved to the recovery positionp3 beyond the determination position p1 on the side of the transfermechanism 54 after left for a while in step S170 of FIG. 5. Then, thefront end t of the printing paper is transferred to the determinationposition p1 in step S190 so that the image printing based on the printdata is resumed. The front end t of the printing paper is moved to therecovery position pa which is closer to the transfer mechanism 54 thanthe determination position p1. The transfer direction of the printingpaper is reversed at the recovery position p3, and not at thedetermination position p1. When there is a reverse in the transferdirection of the printing paper, an error may occur in the transferamount of the printing paper due to the structure of the transfermechanism 54. Accordingly, if the printing paper is returned to thedetermination position p1 directly from the hold position ph, theposition where the image printing should be continued is misaligned,resulting in that the print quality may be deteriorated. Thus, avoidanceof the reverse in the transfer direction at the determination positionp1 achieves a beneficial effect on preventing misalignment of theposition where the image printing should be continued and helps maintainhigh print quality.

The ink amount when determined whether the print state is “heavy-duty”in step S150 of FIG. 5 can be changed according to the paper sizedesignated in the paper size designation process in FIG. 7.

The CPU 41 of the control portion 40 acquires the size data representingthe paper size of the printing paper in the paper size designationprocess in FIG. 7. The CPU 41 can determine whether the print state is“heavy-duty” based on the paper size indicated in the size data.

Even if it is determined that the print state is not “heavy-duty” instep S150 of FIG. 5, it is possible that subtle deformation may occur inthe front portion of the printing paper. This happens when the inkamount ejected onto the front portion of the printing paper is a littleless than the ink amount “enough to cause deformation”. In this case, asshown in FIG. 8A, the front portion t0 of the printing paper partiallyloses contact with the platen 60. Since a part of the printing papergets close to the print head 51, the print quality is deteriorated. Toavoid this situation, the ink amount “enough to cause deformation” ofthe printing paper used when determined whether the print state is“heavy-duty” in step S150 may be set lower. However, the lower the inkamount is set, the more frequently the printing based on the print datais interrupted (steps S160 to S190 are repeated more often), producingundesirable results that the time required for printing by the printportion 50 becomes longer. In the present embodiment, the above problemis solved by way of the shape of the platen 60.

As mentioned before, the horizontal position of the feed ribs 62 of theplaten 60 with respect to the body part of the platen 60 is designed tobe higher than that of the discharge ribs 64. Also, there is clearance66 between the feed ribs 62 and the discharge ribs 64 where no rib isprovided (see FIG. 3). As a result, even if subtle deformation occurs inthe printing paper transferred from the transfer mechanism 54, resultingin that the front portion to loses contact with the platen 60 (see FIG.8A), the front end t is lowered once when passed from the feed ribs 62to the discharge ribs 64 over the clearance 66 without ribs (see FIG.8B). This brings the front portion t0 close to the feed ribs 62.Furthermore, when the front end t of the printing paper abuts the upperpart of the discharge ribs 64 positioned lower than the feed ribs 62(see FIG. 8C), the front portion to of the printing paper is broughtclose to the feed ribs 62. In this manner, separation of the frontportion to of the printing paper from the platen 60 can be inhibited.

In the area 60 a in this platen 60 where only a discharge rib 64 isprovided, one end of the discharge rib 64 is chamfered on the side ofthe transfer mechanism 54. As a result, even if the aforementionedsubtle deformation occurs at a section of the front portion to passingover the area 60 a or the front end t of the printing paper bows due toits own weight (see FIG. 9A), the front end t can be properly guidedtoward the discharge mechanism 55.

Second Embodiment

A complex apparatus 2 is provided with the components identical to thosein the complex apparatus 1 in the first embodiment. Therefore, only thedifference is explained hereafter. The complex apparatus 2 constitutes aprint system together with the PC 100.

(Print Data Transmission Process by PC 100)

Steps in the print data transmission process performed by a CPU mountedon the PC 100 are described below by way of FIG. 10. The steps in theprint data transmission process are processed by a printer driverinstalled in the PC 100. The print data transmission process is startedwhen prescribed operation for printing an image is carried out inapplication software running on the PC 100. When such operation is made,not only the image data but also the data representing the paper type tobe used for the printing, paper thickness, and paper size are deliveredto the printer driver. The aforementioned “paper type” includes, forexample., standard paper, OHP (overhead projector) sheet and exclusiveglossy paper. The “paper thickness” indicates whether the paper is cardpaper.

First of all, a drop number counter and a card paper flag are reset,respectively (S410). In this step, the drop number counter for countingthe number of drops to be ejected by the complex apparatus 2 (print head61 of the print portion 50) is reset. Also, the card paper flag is setto “0”.

Then, the print data based on the image data is generated (S420).

Next, the type of printing paper to be used is determined (S430). Inthis step., it is determined whether the printing paper to be used isthe standard paper or other paper based on the data delivered togetherwith the image data.

If it is determined in step S430 that the printing paper is the OHPsheet or exclusive glossy paper (S430: NO), the sub-data correspondingto each primary scan of the print data is transmitted to the complexapparatus 2 in a sequential order (S440). This is because such paper donot absorb water and deformation is not likely to occur. In this case,it is not necessary to count the number of ink drops ejected on theprinting paper.

If the print data for all the pages are not yet transmitted to thecomplex apparatus 2 (S450: NO), the process returns to step S440. If theprint data for all the pages have been transmitted (S450: YES), thepresent print data transmission process is ended.

If it is determined in step S430 that the printing paper to be used isthe standard paper (S430: YES), the thickness of the printing paper ischecked (S460). In this step, it is determined whether the printingpaper is card paper based on the data delivered together with the imagedata.

If it is determined in step S460 that the printing paper is card papersuch as a post card (S460: YES), the card paper flag is set to “1”(S470).

After step S470 is completed, or, if it is determined, in step 8460 thatthe printing paper is not card paper (S460: NO), drop density of inkwhich is assumed to be ejected onto the printing paper when the imageshown in the image data is printed by the complex apparatus 2 iscalculated (S480). In this step, when the image shown in the image datais printed by the print portion 50 (print head 51) of the complexapparatus 2, the number of ink drops expected to be ejected onto thefront portion (the side of the front end t in FIG. 6) of the printingpaper is counted, during from the start of the printing until theprinting paper reaches to the determination position p1 shown in FIG. 6.Then, based on the count value obtained and the paper size shown in thedata delivered together with the image data, the average drop density,in the area on the printing paper, of ink to be ejected is calculated.

Next, it is determined whether the ink drop density calculated in stepS480 exceeds a preset value which is “enough to cause deformation” inthe front portion of the printing paper (S490). The preset value isdetermined by dividing the number of ink drops ejected onto the frontportion of the printing paper by a ratio of the width of the printingpaper to the letter width. In this case, a half amount of ink ejectedfrom all the nozzles of the print head 51 to the letter width in thenormal printing mode is used as the base.

If it is determined in step S490 that the density exceeds the presetvalue (S490: YES) and if the card paper flag is set to “1” (S500: YES),first command data is added to the sub-data showing the ink ejectionpattern and the transfer amount of the printing paper in the firstprimary scan of the print data (S510). On the other hand, if it isdetermined in step S490 that the density exceeds the preset value (S490:YES) and if the card paper flag is set to “0” (S500: NO), second commanddata is added to the aforementioned sub-data (S520). The command dataadded in step S510, S520 respectively includes a command for making thecomplex apparatus 2 execute steps corresponding to S160 to S190 of FIG.5. Only difference between the first and second command data lies in thestandby time in step S170. These command data are added to the transferinstructions which are given when the front end t of the printing paperreaches to the determination position p1 shown in FIG. 6 at the nextsecondary scan. In the print process of the CPU 41, it is determinedthat the print density in the front portion of the printing paper hasexceeded the preset value if one of the above command data is detected,and further performs operation of straightening the front portion of thepaper. In the present embodiment, the standby time is set to two secondsin the first command data, and four seconds in the second command data.

After step S510, S520 is completed, or, if it is determined in step S490that the density does not exceed the preset value (S490: NO), thesub-data corresponding to the respective secondary scans of the printdata are transmitted to the complex apparatus 2 by turns (S530).

If it is determined that the print data for all the pages, generated instep S420, are not transmitted to the complex apparatus 2 (S540: NO),the drop number counter is reset (S550) and the process returns to stepS480. If the print data for all the pages have been transmitted (S540:YES), the present print data transmission process is ended.

(Print Process by CPU 41)

Steps in the print process performed by the CPU 41 of the controlportion 40 are described below by way of FIG. 11. This print process isonly partially different from the print process in the first embodiment(FIG. 5). Accordingly, only the difference will be explained in detailshereafter. Steps having the numbers identical to those in the firstembodiment are identical steps to those in the first embodiment.

First, a paper is fed from the print portion 10 to the print portion 50(silo).

Then, the drop counter is cleared (S120).

Next, a piece of sub-data for one primary scan is taken out from theprint data (S130).

It is determined whether the sub-data obtained in step S130 hasadditional command data (S610). The command data checked in this step isthe data added by the PC 100 in step S510 or S520 of FIG. 10.

If it is determined in step S610 that the command data is added to theobtained sub-data (S610: YES), the print density in the front portion ofthe printing paper is considered to have exceeded the preset value.Therefore, the front end t of the printing paper is transferred to thedischarge mechanism 55 (S180).

The front portion of the printing paper is held between the respectiverollers 55 b, 55 c of the discharge mechanism 55 and left as it is forthe predetermined time (S620). In this step, if the command data addedto the sub-data obtained in step S130 is the “first command data”, theprinting paper is held between the rollers 55 b, 55 c for two seconds.If the command data is the “second command data”, the printing paper isheld therebetween for four seconds.

Then, the front end t of the printing paper is moved to the recoveryposition p3 which is spaced apart from the determination position p1 inthe counter area A by a predetermined distance on the side of thetransfer mechanism 54 (S180).

The front end t of the printing paper is then transferred to thedetermination position p1 in the counter area A (S190).

After step S190 is completed, or, when it is determined in step S610that no command data is added to the sub-data obtained in step S130(8610: NO), the printing paper is transferred to the normal transferdirection by the transfer amount indicated in the sub-data obtained instep S130 (S200).

Next, ink is ejected according to the ejection pattern shown in thesub-data obtained in step S130 while the print head 51 is moved to theprimary scanning direction by the carriage motor 53 (S210).

Next, it is determined whether the sub-data corresponding to the nextprimary scan exists (S220). If the sub-data exists (S220: YES), theprocess returns to step S130.

After steps S130 to S220 are repeated as necessary and if it isdetermined that no sub-data corresponding to the next primary scanexists (S220: NO), the printing paper is discharged from the printportion 50 to the discharge tray 34 (S230). The present print process isended.

[Effects in the Second Embodiment]

According to the above complex apparatus 2, when the drop density of inkejected onto the front portion of the printing paper (i.e. ink densityon the front portion of the printing paper) becomes the density “enoughto cause deformation” of the front portion, the image printing based onthe print data is interrupted in the same manner as in the firstembodiment, and steps S160 to S190 are performed. Consequently,deformation of the printing paper due to the drying of ink ejected ontothe printing paper can be prevented. Also, misalignment of the positionwhere the image printing should be resumed can be avoided.

[Modifications]

In the above, embodiments of the present invention have been described.However, the present invention should not be limited to the particularembodiments described above, and other modifications and variations maybe possible.

For instance, in the above embodiments, the configuration of the printsystem of the present embodiment is applied to the complex apparatus 1or a system comprised of the complex apparatus 2 and the PC 100.However, the print system of the present invention may be comprised ofthe apparatus other than the complex apparatus provided that theapparatus comprises a unit corresponding to the print portion 50.

In the above embodiments, steps shown in FIG. 5, 11 are performed by thecomputer system of the CPU 41 in the complex apparatus. However, part orall of these steps may be executed by another computer system connectedwith the complex apparatus by a wire/radio signal transmission path.

In the above embodiments, steps in FIG. 10 are performed by the CPUmounted on the PC 100. However, part or all of these steps may beexecuted by another computer system connected with the complex apparatusby a wire/radio signal transmission path.

In the above embodiments, steps in FIG. 5, 11 are executed according tothe manner stored in the ROM 42 of the complex apparatus. However, ifthe complex apparatus is configured to exchange data with a medium suchas a FD or a memory card, the above steps may be performed according tothe manner recorded in such a medium.

In the above embodiments, the CPU 41 of the control portion 40 directlycontrols all the components (except for motors) of the complexapparatus. However, part or all of the components of the complexapparatus may be controlled indirectly via an integrated circuit (suchas ASIC (application specific integrated circuit)).

In the above first embodiment, the number of ink drops ejected from theprint head 51 is counted by the drop counter in real time. However, inkejection times known from the ejection pattern indicated in the printdata may be counted in advance by a dot counter. In this case, the dotcounter is reset in step S120 of FIG. 5. In step S130, a piece ofsub-data is taken out from the print data and the ink ejection timesspecified by the obtained sub-data is counted.

In the above first embodiment, the standby time in step S170 of FIG. 5is the time experimentally determined considering the time assumednecessary to dry the ink on the printing paper and the time requiredtill the portion deformed due to the ink moisture is substantiallyrecovered following the drying of ink. However, in step S170, thestandby time may be determined by calculation (or experimentallyobtained) based on the parameters (such as material) of the printingpaper.

In the above first embodiment, the ink amount for determining whetherthe print state is “heavy-duty” in step S150 of FIG. 6 is modifiedaccording to the paper size designated in the paper size designationprocess of FIG. 7. However, the ink amount for use in this determinationmay be modified based on the parameters other than the paper size, moreparticularly, the thickness or the material of the printing paper. Inthis case, the thickness or the material of the paper instead of thesize is selected in step S310 of FIG. 7. The data showing such parameteris stored in the RAM 48. The ink amount “enough to cause deformation”according to the thickness, material of the printing paper is obtainedin advance by experiments. In step S150 of FIG. 6, the ink amount“enough to cause deformation” according to the thickness, materialindicated in the data stored in the RAM 43 is used for the determinationof whether the print state is “heavy-duty”. The CPU 41 of the controlportion 40 constituted as such can obtain the data showing the thicknessor material of the paper in the paper size designation process in FIG.7. Based on the thickness or material of the paper indicated in thedata, whether the print state is “heavy-duty” can be determined.

Moreover, if the print data is the data representing the paper size, theink amount for use in the determination of whether the print state is“heavy-duty” may be modified according to the paper size indicated inthe print data.

In the above first embodiment, the switching of the modes between thedry mode and the regular mode may be performed in response to theinstructions from the outside. In the dry mode, steps S120 and afterwardin FIG. 5 are performed to dry the ink on the printing paper. In theregular mode, steps S120 and afterward in FIG. 5 are not executed. Inthis case, as shown in FIG. 12, the current mode is checked (S710) afterstep S110. If the current mode is the dry mode (S710: YES), the processproceeds to step S120. If the current mode is the regular mode (S710:NO), the following steps are performed. First, a piece of sub-data istaken out in the same manner as in step S130 (S720). Then, the printingpaper is transferred as in step S200 (S730). After the ink is ejected inthe same manner as in step S210, whether the next sub-data exists ischecked as in step S220. If the sub-data exists, the process returns tostep S720. If no sub-data exists, the print process is ended.

In order to change modes in the above constitution, it is preferablethat the operation keypad 22 of the user I/F 20 is designed to becapable of switching the modes, for example. It is also preferable that,when the print data is transmitted from the PC 100, third command datafor selecting the mode may be added to the print data. Particularly,when the print data is transmitted from the PC 100, a print datatransmission process as shown in FIG. 13 is performed. Steps in thisprint data transmission process are processed by a printer driverinstalled in the PC 100. The print data transmission process is startedwhen prescribed operation for printing an image is carried out inapplication software running on the PC 100. When such operation is made,not only the image data but also the data representing the paper type tobe used for the printing, such as standard paper, OHP (overheadprojector) sheet, exclusive glossy paper, are delivered to the printerdriver.

First of all, the print data based on the image data is generated(S810). Then the type of the printing paper is checked (S820). In stepS820, if the printing paper is the standard paper (S820: YES), the thirdcommand data for executing the printing in the dry mode is added to theprint data (S830). After step S830, or if it is determined that theprinting paper is the OHP sheet or the exclusive glossy paper (S820:NO), the print data is transmitted to the complex apparatus 2 (S840).

1. A print system comprising: a print head that ejects ink; an upstreamtransfer device that is provided in a feed path extending from a feedposition to a counter area facing the print head, and transfers arecording medium along the feed path; a downstream transfer device thatis provided in a discharge path extending from the counter area to adischarge position, and transfers the recording medium along thedischarge path; a print instruction device that provides instructionsfor the upstream or downstream transfer device to transfer the recordingmedium and for the print head to eject ink in turn based on print datarepresenting a predetermined image shown in an ejection pattern of inkto print the image upon the recording medium; an ink amount measurementdevice that measures the amount of ink ejected from the print head andstores the amount as a measurement value; and an ink amountdetermination device that determines whether the measurement valuestored in the ink amount measurement device exceeds a preset value whenthe recording medium is transferred by the upstream transfer device anda front end of the recording medium is moved to a first position,wherein the downstream transfer device is comprised of a drive rollerand a driven roller so that the recording medium can be passed throughbetween the drive roller and the driven roller, and the printinstruction device discontinues the instructions based on the print dataif it is determined by the ink amount determination device that themeasurement value exceeds the preset value, and instructs the upstreamtransfer device to transfer the recording medium from the first positionto the downstream transfer device, and when the front end of therecording medium is transferred to the downstream transfer device to beheld between the drive roller and the driven roller, further instructsthe upstream transfer device to transfer the recording medium to asecond position located at least downstream of the first position, thesecond position being the position where the printing should beperformed next to the printing at the first position, so that theinstructions based on the print data are continued when the front end ofthe recording medium has reached to the second position.
 2. The printsystem as set forth in claim 1 wherein said ink amount measurementdevice measures the amount of ink based on the number of ink dropsejected from the print head.
 3. The print system as set forth in claim 1wherein said print instruction device stands by for a predetermined timein a state that the recording medium is transferred to the downstreamtransfer device and the front end of the recording medium is heldbetween the drive roller and the driven roller.
 4. The print system asset forth in claim 1 wherein said print instruction device, when therecording medium is transferred to the downstream transfer device andthe front end of the recording medium is held between the drive rollerand the driven roller, instructs the upstream transfer device totransfer the recording medium from the downstream transfer device to athird position which is spaced apart from the first position by apredetermined distance on the side of the feed position, and when thefront end of the recording medium is moved to the third positioninstructs the upstream transfer device to transfer the recording mediumfrom the third position to the first position, so that the instructionsbased on the print data are resumed, when the front end of the recordingmedium is moved to the first position.
 5. The print system as set forthin claim 1 further comprising a recording medium parameter acquisitiondevice that obtains parameter data representing parameters of therecording medium from the outside, wherein said ink amount determinationdevice modifies a preset value used for the determination of themeasurement value according to the parameters shown as the parameterdata obtained by the recording medium parameter acquisition device. 6.The print system as set forth in claim 5 further comprising a parameterinput device that allows a user to input the parameters of the recordingmedium, wherein the recording medium parameter acquisition deviceobtains the parameters inputted from the parameter input device as saidparameter data.
 7. The print system as set forth in claim 5 wherein saidrecording medium parameter acquisition device obtains data expressingthe size of the recording medium as said parameter data.
 8. The printsystem as set forth in claim 5 wherein said recording medium parameteracquisition device obtains data expressing the thickness of therecording medium as said parameter data.
 9. The print system as setforth in claim 5 wherein said recording medium parameter, acquisitiondevice obtains data expressing the material of the recording medium assaid parameter data.
 10. The print system as set forth in claim 1further comprising a mode switching device that switches the operationmode of the print system between a suspension mode and a regular mode,in the suspension mode the instructions based on the print data from theprint instruction device being interrupted according to thedetermination result of said ink amount determination device, and in theregular mode the instructions not being interrupted regardless of thedetermination result of the ink amount determination device.
 11. A printsystem comprising a printer and a terminal apparatus, the printercomprising: a print head that ejects ink; an upstream transfer devicethat is provided in a feed path extending from a feed position to acounter area facing the print head, and transfers a recording mediumalong the feed path; a downstream transfer device that is provided in adischarge path extending from the counter area to a discharge position,and transfers the recording medium along the discharge path; and a printinstruction device that provides instructions for the upstream ordownstream transfer device to transfer the recording medium and for theprint head to eject ink in turn based on print data representing apredetermined image shown in an ejection pattern of ink to print theimage upon the recording medium, the terminal apparatus comprising: anink amount measurement device that measures the amount of ink ejectedfrom the print head and stores the amount as a measurement value; and anink amount determination device that determines whether the measurementvalue stored in the ink amount measurement device exceeds a preset valuewhen the recording medium is transferred by the upstream transfer deviceand a front end of the recording medium is moved to a first position,wherein said printer and said terminal apparatus are communicable toeach other for data exchange, the downstream transfer device iscomprised of a drive roller and a driven roller so that the recordingmedium can be passed through between the drive roller and the drivenroller, and the print instruction device discontinues the instructionsbased on the print data if it is determined by the ink amountdetermination device that the measurement value exceeds the presetvalue, and instructs the upstream transfer device to transfer therecording medium from the first position to the downstream transferdevice, and when the front end of the recording medium is transferred tothe downstream transfer device to be held between the drive roller andthe driven roller, further instructs the upstream transfer device totransfer the recording medium to a second position located at leastdownstream of the first position, the second position being the positionwhere the printing should be performed next to the printing at the firstposition, so that the instructions based on the print data are continuedwhen the front end of the recording medium has reached to the secondposition.
 12. The print system as set forth in claim 11 wherein saidprinter comprises a recording medium parameter acquisition device thatobtains parameter data representing parameters of the recording mediumfrom the outside.
 13. The print system as set forth in claim 12 whereinsaid printer comprises a parameter input device that allows a user toinput the parameters of the recording medium.
 14. The print system asset forth in claim 11 wherein said printer comprises a mode switchingdevice that switches the operation mode of the print system between asuspension mode and a regular mode, in the suspension mode theinstructions based on the print data from the print instruction devicebeing interrupted according to the determination result of said inkamount determination device, and in the regular mode the instructionsnot being interrupted regardless of the determination result of the inkamount determination device.
 15. The print system as set forth in claim11 wherein said terminal apparatus comprises a recording mediumparameter acquisition device that obtains parameter data representingparameters of the recording medium from the outside.
 16. The printsystem as set forth in claim 15 wherein said terminal apparatuscomprises a parameter input device that allows a user to input theparameters of the recording medium.
 17. The print system as set forth inclaim 11 wherein said terminal apparatus comprises a mode switchingdevice that switches the operation mode of the print system between asuspension mode and a regular mode, in the suspension mode theinstructions based on the print data from the print instruction devicebeing interrupted according to the determination result of said inkamount determination device, and in the regular mode the instructionsnot being interrupted regardless of the determination result of the inkamount determination device.
 18. A terminal apparatus comprising: an inkamount measurement device that measures an amount of ink ejected from aprint head and stores the amount as a measurement value; an ink amountdetermination device that determines whether the measurement valuestored in the ink amount measurement device exceeds a preset value whena recording medium is transferred by an upstream transfer device and afront end of the recording medium is moved to a first position; and amode switching device that switches the operation mode of a print systembetween a suspension mode and a regular mode, in the suspension modeinstructions based on the print data from a print instruction devicebeing interrupted according to determination result of said ink amountdetermination device, and in the regular mode the instructions not beinginterrupted regardless of the determination result of the ink amountdetermination device.
 19. The terminal apparatus as set forth in claim18 further comprising a recording medium parameter acquisition devicethat obtains parameter data representing parameters of the recordingmedium from the outside.
 20. The terminal apparatus as set forth inclaim 18 further comprising a parameter input device that allows a userto input the parameters of the recording medium.
 21. A printercomprising: a print head that ejects ink; an upstream transfer devicethat is provided in a feed path extending from a feed position to acounter area facing the print head, and transfers a recording mediumalong the feed path; a downstream transfer device that is provided in adischarge path extending from the counter area to a discharge position,and transfers the recording medium along the discharge path; and a printinstruction device that provides instructions for the upstream ordownstream transfer device to transfer the recording medium and for theprint head to eject ink in turn based on print data representing apredetermined image shown in an ejection pattern of ink to print theimage upon the recording medium, wherein the downstream transfer deviceis comprised of a drive roller and a driven roller so that the recordingmedium can be passed through between the drive roller and the drivenroller, and the print instruction device discontinues the instructionsbased on the print data if it is determined by an ink amountdetermination device that a measurement value exceeds the preset value,and instructs the upstream transfer device to transfer the recordingmedium from a first position to the downstream transfer device, and whena front end of the recording medium is transferred to the downstreamtransfer device to be held between the drive roller and the drivenroller, further instructs the upstream transfer device to transfer therecording medium to a second position located at least downstream of thefirst position, the second position being the position where theprinting should be performed next to the printing at the first position,so that the instructions based on the print data are continued when thefront end of the recording medium has reached to the second position.22. The printer as set forth in claim 21 further comprising a recordingmedium parameter acquisition device that obtains parameter datarepresenting parameters of the recording medium from the outside. 23.The printer as set forth in claim 21 further comprising a parameterinput device set that allows a user to input the parameters of therecording medium.
 24. The printer as set forth in claim 21 furthercomprising a mode switching device that switches the operation mode ofthe print system between a suspension mode and a regular mode, in thesuspension mode the instructions based on the print data from the printinstruction device being interrupted according to the determinationresult of said ink amount determination device, and in the regular modethe instructions not being interrupted regardless of the determinationresult of the ink amount determination device.
 25. A print method for aprint system comprising a print head that ejects ink, an upstreamtransfer device that is provided in a feed path extending from a feedposition to a counter area facing the print head, and transfers arecording medium along the feed path, and a downstream transfer devicethat is provided in a discharge path extending from the counter area toa discharge position, and transfers the recording medium along thedischarge path, the downstream transfer device being comprised of adrive roller and a driven roller, so that the recording medium is passedthrough between the drive roller and the driven roller, a predeterminedimage being printed onto the recording medium when transfer of therecording medium to the upstream or downstream transfer device and inkejection from the print head are instructed in turn based on print datarepresenting the image shown in an ejection pattern of ink, the methodcomprising steps of: measuring the amount of ink ejected from the printhead and storing the amount as a measurement value; determining whetherthe measurement value stored in the ink amount measurement deviceexceeds a preset value when the recording medium is transferred by theupstream transfer device and a front end of the recording medium ismoved to a first position; and discontinuing the instructions based onthe print data if it is determined that the measurement value exceedsthe preset value, and instructing the upstream transfer device totransfer the recording medium from the first position to the downstreamtransfer device, and when the recording medium is transferred to thedownstream transfer device to be held between the drive roller and thedriven roller, further instructing the upstream transfer device totransfer the recording medium to a second position located at leastdownstream of the first position, the second position being the positionwhere the printing should be performed next to the printing at the firstposition, so that the instructions based on the print data are continuedwhen the front end of the recording medium has reached to the secondposition.
 26. A computer-readable medium having computer-readableinstructions, the instructions comprising: instructions for a printinstruction device to provide instructions for an upstream or downstreamtransfer device to transfer a recording medium and for a print head toeject ink in turn based on print data representing a predetermined imageshown in an ejection pattern of ink to print the image upon therecording medium; instructions for an ink amount measurement device tomeasure the amount of ink ejected from the print head and stores theamount as a measurement value; and instructions for an ink amountdetermination device to determine whether the measurement value storedin the ink amount measurement device exceeds a preset value when therecording medium is transferred by the upstream transfer device and afront end of the recording medium is moved to a first position, whereinthe downstream transfer device is comprised of a drive roller and adriven roller so that the recording medium can be passed through betweenthe drive roller and the driven roller, and the print instruction devicediscontinues the instructions based on the print data if it isdetermined by the ink amount determination device that the measurementvalue exceeds the preset value, and instructs the upstream transferdevice to transfer the recording medium from the first position to thedownstream transfer device, and when the front end of the recordingmedium is transferred to the downstream transfer device to be heldbetween the drive roller and the driven roller, further instructs theupstream transfer device to transfer the recording medium to a secondposition located at least downstream of the first position, the secondposition being the position where the printing should be performed nextto the printing at the first position, so that the instructions based onthe print data are continued when the front end of the recording mediumhas reached to the second position.